5A8R:
reference: Didehydroaspartate Modification in Methyl-Coenzyme M Reductase Catalyzing Methane Formation., Wagner T, Kahnt J, Ermler U, Shima S, Angew Chem Int Ed Engl. 2016 Jul 28. doi: 10.1002/anie.201603882. PMID: 27467699

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).